Microsoft isn't nuts. They simply missed mobile. Microsoft almost missed the Internet, and retained some of their dominance only after decisive top-down action and investment. By the time Microsoft understood what was happening in mobile, it was too late. The fiasco was compounded by Ballmer's indecisive reaction, but it was already set in motion. Anything Microsoft does with mobile, perhaps short of something that l…
Microsoft's current moves are about the tablet space. They think the dominant device form factor will be tablets, not laptops, so they're trying to reposition windows to be a tablet-friendly OS, but have the problem that people don't care about win32 on a tablet, but they do want apps and those apps must be designed for mobile. A lot of what they're doing makes sense from the perspective of wanting to be a player in the tablet space : the unified OS and app store strategy which they are working on now, windows 8, windows rt, surface, the Nokia buyout, and so on.